1. Field of the Invention
The present invention relates to farm implements and, more particularly, to an air conveying apparatus for replenishing particulate material such as seed, fertilizer, herbicide or insecticide in one or more tanks of an air seeder. The invention may be used with other farm implements such as planters or fertilizer application equipment.
2. Description of the Related Art
Air seeder systems include a traction unit with an air cart in tow and frequently include a third unit such as a cultivator either intermediate the traction unit and air cart or towed behind the air cart. Agricultural implements that employ an air seeder system to apply seed, fertilizer, or other particulate material, either sub-surface or to the surface of a farm field, typically have a material supply source such as one or more tanks that are loaded with the particulate material. The tanks have or are associated with a metering device, which typically consists of a rotating element, which meters the particulate material from the tanks into a set of distribution channels, such as conduits, hoses, etc., for application to the farm field. In most systems, a pneumatic source such as a fan or blower provides air to convey and distribute material through the distribution channels. Periodically, the tank's supply of particulate material must be replenished. Typically, a screw auger or belt conveyor feeds the material from a source such as a supply vehicle to the tank. Grain augers, conveyor belts and similar mechanical seed handling equipment may cause damage to certain types of seeds. The conveying of canola seeds in particular is a delicate process. Seeds are expensive and physical damage to seeds may affect their germination and germination rate, thus, damage to the seeds while filling the tanks should be minimized.
A departure from these mechanical seed handling techniques is shown in U.S. patent application Ser. No. 14/301,717 filed Jun. 11, 2014. The technique disclosed therein employs an air conveying system where an air flow, either from the air cart fan or from a dedicated pneumatic source, is supplied to a material reservoir, such as a seed hopper, where that air flow passes through one or more restrictions to create a region of increased air velocity and reduced air pressure and a so-called venturi effect. The venturi effect essentially creates a suction effect to minimize the contact friction of particles against the bottom portions of the hose and for ingesting as many particles as possible of agricultural material from the hopper providing an air entrained flow of material. This air flow and material particles are conveyed to the tank where the material is deposited and excess air vented. The air conveying systems significantly reduce seed damage, however the potential for damage to seeds and other fragile agricultural products remains. Moreover, the products tend to accumulate more in some tank areas than others resulting in a non-uniform product distribution and corresponding non-uniformity of product delivery to the metering system.
What is needed in the art is a gentile yet efficient product handling system for fragile materials.